Gök, SÖnal, AÇinar, MGEvinç, A2024-07-182024-07-18http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/7264ELSEVIER SCIENCE BVArticleThe effect of a leukotriene D-4 receptor antagonist, (3-(3-(2-(7-chloro-2-quinolinyl)ethenyl) amino-3-oxo plopyl)thio)methyl)thio) propanoic acid (L-660,711; MK-571), was investigated on nociceptive responses in mice using three different assays: acetic-acid-induced abdominal constrictions, formalin response and tail-flick test. MK-571 (8-32 mg/kg, i.v.) produced dose-dependent protection against acetic-acid-induced abdominal constriction (ED50 = 30 mg/kg). The compound (10-80 mg/kg, i.p.) was also effective, in a dose-dependent manner, on the second phase of the formalin response (ED50 = 26 mg/kg). However, it had no effect on the first phase of the formalin response and in the tail-flick test. Naloxone (1 mg/kg, i.v.), an opioid antagonist, almost completely blocked the antinociceptive effect of MK-571 in both acetic-acid-induced abdominal constriction and the second phase of the formalin test. These results provide evidence for an antinociceptive action of MK-571 at peripheral sites and suggest that opioid mechanisms are involved. (C) 1999 Elsevier Science B.V. All rights reserved.FORMALIN TEST